Capture testcase for unknown test failures in the JUnit Xml

Testing Done:
Travis CI: https://travis-ci.org/pantsbuild/pants/builds/176145705

When the Mockito test runner comes across a mock that is unneeded it calls the test listener with a test failure for an unknown test case name.  We want to capture these failures as testcases in the xml output.

e.g.

```
Following stubbings are unnecessary (click to navigate to relevant line of code):
  1. -> at com.example.SampleTest.setUp(SampleTest.java:63)
Please remove unnecessary stubbings or use 'silent' option. More info: javadoc for UnnecessaryStubbingException class.
	at org.mockito.internal.exceptions.Reporter.formatUnncessaryStubbingException(Reporter.java:838)
	at org.mockito.internal.junit.UnnecessaryStubbingsReporter.validateUnusedStubs(UnnecessaryStubbingsReporter.java:34)
	at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:49)
	at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:104)
```

Bugs closed: 4054

Reviewed at https://rbcommons.com/s/twitter/r/4377/

3rdparty/jvm/org/mockito/BUILD

@@ -0,0 +1,9 @@
+# Copyright 2016 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+jar_library(
+  name='mockito-core',
+  jars=[
+    jar(org='org.mockito', name='mockito-core', rev='2.2.16'),
+  ],
+)

src/java/org/pantsbuild/tools/junit/impl/AntJunitXmlReportListener.java

@@ -420,9 +420,17 @@ public void testFailure(Failure failure) throws java.lang.Exception {
         // problem with initialization and we won't get a testFinished callback so
         // call finish here.
         testCase.finished();
-        suite.testCases.clear();
-        suite.testCases.add(testCase);
-        suite.finished();
+        if (suite != null) {
+          suite.testCases.clear();
+          suite.testCases.add(testCase);
+          suite.finished();
+        }
+      } else {
+        testCase.finished();
+        testCase.setError(exception);
+        if (suite != null) {
+          suite.testCases.add(testCase);
+        }
       }
     } else {
       if (isFailure) {

tests/java/org/pantsbuild/tools/junit/impl/XmlReportTest.java

@@ -26,6 +26,7 @@
 import org.pantsbuild.tools.junit.lib.XmlReportFailingTestRunnerTest;
 import org.pantsbuild.tools.junit.lib.XmlReportFirstTestIngoredTest;
 import org.pantsbuild.tools.junit.lib.XmlReportIgnoredTestSuiteTest;
+import org.pantsbuild.tools.junit.lib.XmlReportMockitoStubbingTest;
 import org.pantsbuild.tools.junit.lib.XmlReportTestSuite;
 
 import static org.hamcrest.CoreMatchers.containsString;
@@ -122,6 +123,35 @@ public void testXmlReportAllIgnored() throws Exception {
     assertEquals(testClassName, testSuite.getName());
   }
 
+  @Test
+  public void testXmlReportMockitoUnnecessaryStubbing() throws Exception {
+    String testClassName = XmlReportMockitoStubbingTest.class.getCanonicalName();
+    AntJunitXmlReportListener.TestSuite testSuite = runTestAndParseXml(testClassName, true);
+
+    assertNotNull(testSuite);
+    assertEquals(1, testSuite.getTests());
+    assertEquals(0, testSuite.getFailures());
+    assertEquals(1, testSuite.getErrors());
+    assertEquals(0, testSuite.getSkipped());
+    assertTrue(Float.parseFloat(testSuite.getTime()) > 0);
+    assertEquals(testClassName, testSuite.getName());
+
+    List<AntJunitXmlReportListener.TestCase> testCases = testSuite.getTestCases();
+    assertEquals(2, testCases.size());
+    sortTestCasesByName(testCases);
+
+    AntJunitXmlReportListener.TestCase errorTestCase = testCases.get(1);
+    assertEquals(testClassName, errorTestCase.getClassname());
+    assertEquals("unnecessary Mockito stubbings", errorTestCase.getName());
+    assertEquals("0", errorTestCase.getTime());
+    assertNull(errorTestCase.getFailure());
+    assertThat(errorTestCase.getError().getMessage(),
+        containsString("Unnecessary stubbings detected in test class:"));
+    assertEquals("org.mockito.exceptions.misusing.UnnecessaryStubbingException",
+        errorTestCase.getError().getType());
+    assertThat(errorTestCase.getError().getStacktrace(), containsString(testClassName));
+  }
+
   @Test
   public void testXmlReportFirstTestIgnored() throws Exception {
     String testClassName = XmlReportFirstTestIngoredTest.class.getCanonicalName();

tests/java/org/pantsbuild/tools/junit/lib/BUILD

@@ -11,6 +11,7 @@ java_library(
     '3rdparty:guava',
     '3rdparty:junit',
     '3rdparty/jvm/org/hamcrest:hamcrest-core',
+    '3rdparty/jvm/org/mockito:mockito-core',
     'src/java/org/pantsbuild/junit/annotations',
     'src/java/org/pantsbuild/tools/junit',
   ],

tests/java/org/pantsbuild/tools/junit/lib/XmlReportMockitoStubbingTest.java

@@ -0,0 +1,28 @@
+// Copyright 2016 Pants project contributors (see CONTRIBUTORS.md).
+// Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+package org.pantsbuild.tools.junit.lib;
+
+import javax.net.ssl.SSLSession;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import static org.mockito.Mockito.when;
+
+/**
+ * This test is intentionally under a java_library() BUILD target so it will not be run
+ * on its own. It is run by the ConsoleRunnerTest suite to test ConsoleRunnerImpl.
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class XmlReportMockitoStubbingTest {
+  @Mock SSLSession sslSession;
+
+  @Test
+  public void testUnnecesaryMockingError() {
+    when(sslSession.getCipherSuite()).thenReturn("cipher");
+    Assert.assertTrue(true);
+  }
+}